Method and apparatus for introducing fluids into a hydrocracking reactor

ABSTRACT

The invention provides a method and apparatus for introducing a high-density hydrocarbon liquid into a hydrocracking reactor. The method comprises atomizing the high-density hydrocarbon liquid and injecting the atomized liquid into the hydrocracking reactor. The method may also comprise mixing hydrogen with the high-density hydrocarbon liquid prior to atomizing the high-density hydrocarbon liquid. The apparatus comprises an injection valve for introducing a high-density hydrocarbon liquid into a hydrocracking reactor comprises an atomizer coupled to receive the high-density hydrocarbon liquid. The atomizer comprises a nozzle configured to atomize the high-density hydrocarbon liquid and inject the high-density hydrocarbon liquid into the hydrocracking reactor. The injection valve may also comprise a mixer coupled to receive hydrogen and the high-density hydrocarbon liquid. The mixer may be configured to mix the hydrogen and high-density hydrocarbon liquid and deliver the mixture to the atomizer.

REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.11/312,578 filed on 21 Dec. 2005.

TECHNICAL FIELD

This invention relates to methods and apparatus for introducing fluidsinto reactors for upgrading hydrocarbons. Certain embodiments of theinvention have particular application to introducing hydrogen andhigh-density hydrocarbons into upgrader reactors such as hydrocrackingreactors.

BACKGROUND

High-density hydrocarbons such as heavy oil may be upgraded throughhydrocracking by mixing the oil with hydrogen in the presence of acatalyst under high pressure and temperature in a hydrocracking reactor.The effectiveness of hydrocracking depends in part on the ability ofhydrogen to interact with hydrocarbons. In order to crack long molecularchains of heavy oils, hydrogen needs to reach as many hydrocarbonmolecules as possible. Effective admixture of hydrogen in the mass ofhydrocarbon is therefore desirable.

Various arrangements have been devised to inject hydrogen intohydrocarbons upstream of or within a reactor. U.S. Pat. No. 3,152,981discloses a process of forming a mixture of hydrogen and hydrocarbonswherein a distillate feed is introduced into the reactor through a line.The inventor has determined that this process has limited effectiveness,since the distillate feed is not broken down into minute particles. Thislimits the surface area available for contacting andhydrogen-hydrocarbon interaction. Furthermore, in the absence of bulkliquid disintegration, heat transfer to the hydrocarbons is minimal andlight-weight fractions in the hydrocarbon spray remain in a liquid phaseand absorb hydrogen unnecessarily, thereby reducing the hydrogenavailable to be absorbed by heavier fractions.

U.S. Pat. No. 4,995,961 describes injection of hydrogen into a stream ofoil through spargers designed to mix the two fluids within the reactor.However, the inventor has determined that the relatively large size ofhydrogen bubbles limits both hydrogen dispersion and contact areabetween the fluids.

The present invention provides methods and apparatus for upgradinghydrocarbons that avoid some disadvantages of current hydrocrackingsystems.

SUMMARY

The following embodiments and aspects thereof are described andillustrated in conjunction with systems, tools and methods which aremeant to be exemplary and illustrative, not limiting in scope. Invarious embodiments, one or more of the above-described problems havebeen reduced or eliminated, while other embodiments are directed toother improvements.

One aspect of the invention provides a method for introducing ahigh-density hydrocarbon liquid into a reactor for upgradinghydrocarbons such as a hydrocracking reactor. The method comprisesatomizing the high-density hydrocarbon liquid and injecting the atomizedliquid into the hydrocracking reactor. The method may comprise mixinghydrogen with the high-density hydrocarbon liquid prior to atomizing thehigh-density hydrocarbon liquid.

Another aspect of the invention provides an injection valve forintroducing a high-density hydrocarbon liquid into a hydrocrackingreactor. The injection valve comprises an atomizer coupled to receivethe high-density hydrocarbon liquid. The atomizer comprises a nozzleconfigured to atomize the high-density hydrocarbon liquid and inject thehigh-density hydrocarbon liquid into the hydrocracking reactor. Theinjection valve may also comprise a mixer coupled to receive hydrogenand the high-density hydrocarbon liquid. The mixer may be configured tomix the hydrogen and the high-density hydrocarbon liquid and deliver amixture of hydrogen and high-density hydrocarbon to the atomizer.

In addition to the exemplary aspects and embodiments described above,further aspects and embodiments are shown in the drawings and describedin the following detailed descriptions.

BRIEF DESCRIPTION OF DRAWINGS

Exemplary embodiments are illustrated in referenced figures of thedrawings. The embodiments and Figures disclosed herein are illustrativerather than restrictive.

In drawings which illustrate non-limiting embodiments of the invention:

FIG. 1A schematically illustrates a system for introducing hydrocarbonsinto a hydrocracking reactor according to one embodiment of theinvention;

FIG. 1B schematically illustrates a system for introducing hydrocarbonsinto a hydrocracking reactor according to another embodiment of theinvention;

FIG. 1C schematically illustrates a system for introducing hydrocarbonsinto a hydrocracking reactor according to another embodiment of theinvention;

FIG. 2 shows an injection valve coupled to a hydrocracking reactoraccording to an example embodiment of the invention;

FIG. 3 is a cross-sectional view of the example injection valve of FIG.2;

FIG. 4 is a cross-sectional view of a peripheral swirl device takenalong line 4-4 of FIG. 3;

FIG. 5 is an enlarged cross-sectional view taken along line 5-5 of FIG.4;

FIG. 6 is a cross-sectional view of a central swirl device taken alongline 6-6 of FIG. 3;

FIG. 7 is an enlarged cross-sectional view taken along line 7-7 of FIG.6;

FIG. 8 is a cross-sectional view of a portion of an injection valveaccording to another embodiment of the invention; and,

FIG. 9 is a cross-sectional view of a peripheral swirl device takenalong line 9-9 of FIG. 8.

DESCRIPTION

Throughout the following description specific details are set forth inorder to provide a more thorough understanding to persons skilled in theart. However, well known elements may not have been shown or describedin detail to avoid unnecessarily obscuring the disclosure. Accordingly,the description and drawings are to be regarded in an illustrative,rather than a restrictive, sense.

The invention provides a method for introducing hydrocarbons into anupgrader reactor such as a hydrocracking reactor. The hydrocarbons maycomprise, for example, high-density hydrocarbons such as heavy oil orthe like. The method involves atomizing the hydrocarbons and injectingthem into the reactor. The hydrocarbons may be mixed with hydrogen priorto atomization. Mixing of hydrogen and hydrocarbons may be accomplished,for example, by passing the hydrogen and hydrocarbons through one ormore swirl devices in an injection valve. The method may also includeregulating the pressure in the reactor at least in part by controllingthe rate at which the hydrocarbons are introduced into the reactor.

The invention also provides an apparatus for introducing hydrocarbonsinto an upgrader reactor such as a hydrocracking reactor. The apparatuscomprises an atomizer having a nozzle in fluid communication with thereactor for atomizing high-density hydrocarbons. The apparatus may alsocomprise a mixer for mixing the high-density hydrocarbons with hydrogenprior to atomization. The mixer may comprise one or more swirl devices.A pressure regulator may also be provided to control the rate at whichthe hydrocarbons are introduced into the reactor.

FIG. 1A shows a system 100 for introducing hydrocarbons into ahydrocracking reactor 102 according to one embodiment of the invention.System 100 comprises an atomizer 104 having a nozzle 105 in fluidcommunication with reactor 102. Atomizer 104 receives hydrocarbons froma hydrocarbon supply 106 through a hydrocarbon conduit 107. Thehydrocarbons are atomized by nozzle 105 of atomizer 104 as they areintroduced to reactor 102. Within reactor 102, the atomized hydrocarbonsreact with hydrogen provided to reactor 102 from a hydrogen supply 108through a hydrogen conduit 109. Atomization of the hydrocarbons providesincreased surface area for reactions with hydrogen to occur. One or morecatalysts (not shown) are also provided in reactor 102 to facilitate thereaction of the hydrocarbons with hydrogen.

FIG. 1B shows a system 110 for introducing hydrocarbons into reactor 102according to another embodiment of the invention. System 110 is similarto system 100 of FIG. 1A, except that system 110 comprises a mixer 112in fluid communication with atomizer 104. Mixer 112 receiveshydrocarbons from hydrocarbon supply 106 through hydrocarbon conduit107. Mixer 112 also receives hydrogen from hydrogen supply 108 throughhydrogen conduit 109. The hydrocarbons and hydrogen are mixed togetherin mixer 112 prior to being passed to atomizer 104 for atomization andinjection into reactor 102. Mixer 112 may comprise one or more swirldevices to facilitate thorough mixing of the hydrocarbons and hydrogen,as described below. Optionally, additional hydrogen may be supplieddirectly into reactor 102.

FIG. 1C shows a system 120 for introducing hydrocarbons into reactor 102according to another embodiment of the invention. System 120 is similarto system 110 of FIG. 1B, except that system 120 comprises a pressureregulator 122. Pressure regulator 122 regulates the pressure withinreactor 102 by adjusting the rate of injection of hydrocarbons andhydrogen into reactor 102. In the illustrated embodiment, regulation isachieved by opening and closing nozzle 105 of atomizer 104. The rate ofinjection of hydrocarbons and hydrogen into reactor 102 may be adjustedby varying the degree of opening of nozzle 105. It is to be understoodthat pressure regulator 122 could also be used in a system without amixer such as system 100 of FIG. 1A.

A first portion 122 a of pressure regulator 122 is provided with apressure corresponding to the pressure in reactor 102. This may beaccomplished, for example by providing a portion the reaction productfrom reactor 102 to first portion 122 a through product pressure line124. A second portion 122 b of pressure regulator 122 is provided withhydrocarbons and hydrogen from hydrocarbon supply 106 and hydrogensupply 108 through hydrocarbon pressure line 126 and hydrogen pressureline 128, respectively. Second portion 122 b may comprise two separatechambers (not shown in FIG. 1C) for receiving the hydrocarbons and thehydrogen. A piston 123 is positioned between first portion 122 a andsecond portion 122 b of pressure regulator 122. Piston 123 is coupled toa valve 125 configured to open and close nozzle 105. Increased pressurein reactor 104 is passed to first portion 122 a of pressure regulator122, thereby increasing the force on a first side of piston 123 andurging valve 125 toward a closed position. Increased pressure in eitherhydrocarbon supply 106 or hydrogen supply 108 is passed to secondportion 122 b of pressure regulator 122, thereby increasing the force ona second side of piston 123 and urging valve 125 toward an openposition.

FIGS. 2 to 7 illustrate an injection valve 1 for introducing fluids intoa hydrocracking reactor 2 according to one embodiment of the invention.Injection valve 1 includes a number of specific details which have beenincluded for illustrative purposes. It is to be understood that otherembodiments of the invention may not have all of such details and maylack other features of the embodiment shown in FIGS. 2 to 7, or may havefunctionally equivalent features. Further, individual components orgroups of components of injection valve 1 may be used in combinationwith other apparatus.

FIG. 2 shows an injection valve 1 coupled to a reactor 2. Hydrocarbonssuch as heavy oil are supplied to injection valve 1 by means of conduits6 and 7. Hydrogen is supplied to injection valve 1 by means of conduits8 and 9. Injection valve 1 introduces a mixture of hydrogen and oil toreactor 2 by atomization, as described further below. In reactor 2, theoil reacts with the hydrogen in the presence of a catalyst to producelighter hydrocarbon reaction products. A portion of the reactionproducts produced in reactor 2 is supplied to injection valve 1 by meansof conduit 4 for regulating the pressure in injection valve 1 andreactor 2.

A gas-liquid separator 3 is coupled to injection valve 1 by means ofconduit 5. If the mixture of hydrogen and oil which is to be atomized byinjection valve 1 contains an excess of either hydrogen or oil, themixture is diverted to conduit 5 and provided to gas-liquid separator 3,as described further below.

FIG. 3 is a sectional view of injection valve 1. Injection valve 1comprises an upper body segment 20, an intermediate body segment 30 anda lower body segment 40, all of which may be generally cylindricallyshaped. In the following description and claims, the term “up” (andderivatives thereof) is used to refer to the direction away from reactor2, the term “down” (and derivatives thereof) is used to refer to thedirection toward reactor 2. Upper body segment 20 may be attached tointermediate body segment 30 by a ring member 28. Ring member 28 isconfigured to threadably engage upper segment 20 and hold intermediatebody segment 30 thereagainst. Ring member 28 may comprise two flatsurfaces on its outer circumference for accommodating a suitably sizedwrench. Likewise, intermediate body segment 30 may be attached to lowerbody segment 40 by a ring member 34. Alternatively, body segments 20, 30and 40 could be of unitary construction. Lower body segment 40 comprisesa flange 40 a on a lower portion thereof. Flange 40 a is engageable witha compatible mounting on reactor 2 (see FIG. 2).

A flange 20 a extends radially outwards at an upper portion of segment20. A lid 10 may be attached to flange 20 a by a plurality of bolts 10a. An aperture 18 is defined in the center of lid 10. Aperture 18 issized to accommodate a rod member 17. A tight seal between rod member 17and aperture 18 may be achieved through highly polished surfaces and/ora seal ring designed to withstand high temperature and high pressureconditions.

A spring 16 abuts a spring-seating member 15 a which rests on the upperend of rod 17. Disposed above spring 16 is a spring abutment member 15which may comprise a threaded portion at an upper end thereof. A casing12 may be threadably attached to a shoulder 11 atop lid 10. A threadedaperture 14 is defined in casing 12 and sized to accommodate the upperportion of spring abutment member 15. A nut 13 abuts the top of casing12 and threadably engages the upper portion of spring abutment member15. A shaped (e.g. hexagonal) recess 13 a in the upper end of springabutment member 15 may be used in conjunction with nut 13 for adjustingtension of spring 16 by turning spring abutment member 15 in threadedaperture 14. The lower portion of abutment member 15 may be enlarged toprevent abutment member 15 from being inadvertently removed whilstspring tension is being adjusted.

A relatively large bore 21 is provided in upper body segment 20 forminga cylindrical chamber 22 that is enclosed by lid 10 and an upper portionof a piston member 23. Chamber 22 is in fluid communication with apassage 60 drilled in upper body segment 20. Gas supplied from reactor 2through conduit 4 and passage 60 operates in conjunction with springmember 16 and applies a force directed downward upon piston member 23.Piston member 23 may be affixed to a rod member 17 which extendsupwardly therefrom and abuts spring-seating member 15 a. Piston member23 may also be affixed to a rod member 26 which extends downwardlytherefrom. Alternatively, piston member 23 and rod members 17 and 26could be of unitary construction.

As discussed further below, piston member 23 is operatively coupled to avalve comprising a valve closure member 46 and a seat 45 by means of rodmembers 26, 36, 51 and 49. Piston member 23 works in conjunction withthe valve and another piston member 33 to provide a pressure regulationfunction in injection valve 1. Piston member 23 is slidable in suchmanner that the application of pressure by a fluid on its upper exposedsurface applies a force on valve closure member 46 urging it towardsseat 45. Conversely, pressure applied on the lower exposed surface ofpiston member 23 urges valve closure member 46 away from seat 45.

A smaller-diameter bore 25 disposed below bore 21 accommodates the lowerportion of piston member 23. The diameter of bore 21 may be greater thanthe diameter of bore 25 preferably by an amount on the order of 1.4times, although it is to be understood that a different ratio of thediameters of bores 21 and 25 is possible. Piston member 23 comprises alarger diameter upper portion that generally matches the diameter ofbore 21 and a reduced diameter lower portion that matches the diameterof bore 25. Sealing between piston member 23 and bores 21 and 25 may beprovided through highly polished surfaces and/or seal ring membersdesigned to contain fluids at high pressure and temperature. It is to beunderstood that other suitable arrangements may be used to providesealing between piston 23 and bores 21 and 25. An annular space 22 a isdefined between piston member 23 and upper body segment 20. Annularspace 22 a is in fluid communication with a passage 67, which may beprovided in upper body segment 20 in order to vent annular space 22 a tothe atmosphere to allow unhindered movement of piston member 23.

A circular plate 27 is disposed below piston member 23 near the lowerend of upper body segment 20. Circular plate 27 is of substantialconstruction to withstand high-pressure conditions. A circular aperture29 in the center of circular plate 27 slidingly accommodates rod member36, which is attached to the bottom of rod member 26. Sealing betweenrod member 36 and aperture 29 may be provided through highly polishedsurfaces and/or seal ring members designed to contain fluids at highpressure and temperature, but it is to be understood that other suitablearrangements may be used to provide sealing between rod member 36 andaperture 29. The lower end of rod member 26 is reduced in diameter andengages rod member 36 through a threaded connection. A recess in theinner wall of upper body segment 20 accommodates circular plate 27 andensures that circular plate 27 is concentrically disposed with respectto rod members 26 and 36.

A chamber 24 is defined within bore 25 of upper body segment 20 betweenpiston member 23 and circular plate 27. A passage 61 provided in upperbody segment 20 connects chamber 24 to conduit 6 (see FIG. 2) whichsupplies heavy oil to chamber 24. Pressure exerted by the heavy oil inchamber 24 exerts an upward force on piston member 23, which in turnurges valve closure member 46 away from seat 45. Chamber 24 is also influid communication with a plurality of radial passages 68 a positionedaround circumference of rod member 26. Radial passages 68 a areperpendicular to rod member 26 and provide fluid communication betweenchamber 24 and a swirl device 70 through a central passage 68 extendingalong rod members 26, 36 and 51 and radial passages 68 b in rod member51.

A piston member 33 is attached to rod member 36, for example by suitablewelds. Piston member 33 is in sliding contact with a bore 31 inintermediate body segment 30. Bore 31 may have the same diameter as bore25. Similarly to piston member 23, sealing between bore 31 and pistonmember 33 may be provided through highly polished surfaces and/or sealring members designed to contain fluids at high pressure andtemperature, but it is to be understood that other suitable arrangementsmay be used to provide sealing between piston member 33 and bore 31.

A vent chamber 32 a is defined in bore 31 of intermediate body segment30 between circular plate 27 and piston member 33. A passage 66 providesfluid communication between vent chamber 32 a and the atmosphere andfacilitates motion of piston member 33.

A circular plate 35 is disposed below piston member 33 near the lowerend of intermediate body segment 30. Circular plate 35 is of substantialconstruction to withstand high-pressure conditions. A circular aperture38 in the center of circular plate 35 slidingly accommodates rod member36. Sealing between rod member 36 and aperture 38 may be providedthrough highly polished surfaces and/or seal ring members designed tocontain fluids at high pressure and temperature, but it is to beunderstood that other suitable arrangements may be used to providesealing between rod member 36 and aperture 38. A recess in the innerwall of intermediate body segment 30 accommodates circular plate 35 andensures that circular plate 35 is concentrically disposed with respectto rod member 36.

A chamber 32 is defined in bore 31 of intermediate body segment 30between piston member 33 and circular plate 35. A passage 65 bored inintermediate body segment 30 connects chamber 32 to conduit 8 (see FIG.2) which supplies hydrogen to chamber 32. Pressure exerted by thehydrogen in chamber 32 exerts an upward force on piston member 33, whichin turn urges valve closure member 46 away from seat 45.

The lower end of rod member 36 is reduced in diameter and engages rodmember 51 through a threaded connection. A peripheral swirl device 70and a central swirl device 80 are disposed on rod member 51. Swirldevices 70 and 80 act as mixers to mix heavy oil and hydrogen, asdescribed further below. It is to be understood that either of swirldevices 70 or 80 could be used on its own to mix heavy oil and hydrogen,or other means could be provided to mix heavy oil and hydrogen inaddition to or instead of one or both of swirl devices 70 and 80. It isalso to be understood that one or both of swirl devices 70 and 80 couldbe used to mix fluids in conjunction with other apparatus.

A chamber 54 is defined in a bore 82 of lower body segment 40 betweencircular plate 35 and peripheral swirl device 70. Bore 82 may have thesame diameter as bores 25 and 31 in upper body segment 20 andintermediate body segment 30, respectively. A passage 64 in lower bodysegment 40 connects chamber 54 with conduit 9 (see FIG. 2), whichsupplies hydrogen to chamber 54. Chamber 54 is in fluid communicationwith peripheral swirl device 70 by means of longitudinal passages 72 andradial passages 71 provided in screws 73 (see FIGS. 4 and 5). Chamber 54is also in fluid communication with central swirl device 80 by means ofa plurality of radial passages 69 a and 69 b and longitudinal passages69 provided in rod member 51.

With reference to FIGS. 4 and 5, peripheral swirl device 70 comprises alower plate 70 a and an upper plate 70 b. Lower plate 70 a has anaperture 79 defined in the center thereof which forms an inner annularspace. Distribution plates 74 are positioned between lower and upperplates 70 a and 70 b and shaped to form curved chambers 75. As shown inFIG. 4, chambers 75 may be roughly teardrop-shaped. Screws 73 extendthrough lower and upper plates 70 a and 70 b. Radial passages 71 andlongitudinal passages 72 in screws 73 provide fluid communicationbetween chambers 75 and chamber 54, so that hydrogen may be introducedinto chambers 75. Radial passages 71 and longitudinal passages 72 inscrews 73 may be calibrated in order to adjust the amount of fluidsupplied to peripheral swirl device 70 in relation to the amount offluid supplied to central swirl device 80. The flow rate of hydrogen toperipheral swirl device 70 may be altered by utilizing screws 73 havingvarious passage diameters. The optimal size of passages 71 and 72 may beestablished in relation to various types of heavy oil during theoperation of reactor 2. Nozzles 76 are formed by distribution plates 74at the inner ends of chambers 75, such that hydrogen is expelled fromnozzles 76 into aperture 79 in a generally tangential direction.

In addition to receiving hydrogen from chamber 54, peripheral swirldevice 70 also receives oil from conduit 7 through a passage 62 providedin lower body segment 40. Oil from passage 62 is provided to spaces 78defined between distribution plates 74 and lower and upper plates 70 aand 70 b through an annular groove 62 a. The sizes of annular groove 62a and lower and upper plates 70 a and 70 b are selected such that spaces78 remain in fluid communication with passage 62 throughout the entirerange of motion of peripheral swirl device 70 (which may be caused byunbalanced forces on piston members 23 and 33). Nozzles 77 are formed bydistribution plates 74 at the inner ends of spaces 78, such that oil isexpelled from nozzles 77 into aperture 79 in a generally tangentialdirection. Due to the fact that each nozzle 77 is located between twonozzles 76, the fluids emerging from nozzles 76 and 77 mix intimately.The shapes of nozzles 76 and 77 and the flow rates of hydrogen andhydrocarbons may be selected to provide turbulent mixing near nozzles 76and 77.

With reference to FIGS. 6 and 7, central swirl device 80 comprises alower plate 80 a and an upper plate 80 b affixed to rod member 51 byrivets 81 or other suitable means. Rivets 81 also hold lower and upperplates 80 a and 80 b against each other. A plurality of hydrocarbonchambers 83 and hydrogen chambers 84 may be provided in the uppersurface of lower plate 80 a and/or the lower surface of upper plate 80b. In the illustrated embodiment, central swirl device 80 comprises foureach of hydrocarbon chambers 83 and hydrogen chambers 84, but it is tobe understood that a different number of chambers could be provided.

Hydrocarbon chambers 83 are in fluid communication with chamber 24 bymeans of radial bores 68 b in rod member 51, longitudinal bore 68 in rodmembers 51, 36, and 26, and radial bores 68 a in rod member 26. Eachhydrocarbon chamber 83 has a narrow section in an outward portionthereof which forms a nozzle 86 in fluid communication with annularspace 88. Hydrocarbons from chamber 24 flow into hydrocarbon chambers 83and is directed radially outwardly toward nozzles 86. The walls ofhydrocarbon chamber 83 are curved to impart a swirling motion to thefluid exiting through nozzle 86.

Hydrogen chambers 84 are in fluid communication with chamber 54 by meansof radial passages 69 a and 69 b and longitudinal passage 69 in rodmember 51. Each hydrogen chamber 84 has a narrow section in an outwardportion thereof which forms a nozzle 85 which merges with one of nozzles86. Hydrogen from chamber 54 flows through each hydrogen chamber 84toward nozzle 85 which accelerates and directs the hydrogen against thestream of hydrocarbons flowing through the corresponding nozzle 86. Thecollision of the hydrogen and hydrocarbons at high velocity formsvortices that intimately mix the fluids. The resulting stream isexpelled with a swirling motion into annular space 88 by nozzles 86.

Returning to FIG. 3, the lower portion of lower body segment 40 definesa bore 47 of reduced diameter that in sliding contact with a rod member49. Rod member 49 is attached to the bottom of rod member 51. Valveclosure member 46 is attached to the bottom of rod member 49. Thediameter of bore 47 in relation to that of rod member 49 is such thatbore 47 guides the sliding movement of valve closure member 46 andcenters it concentrically with seat 45.

A chamber 52 is defined at the lower portion of bore 82. Fluid emergingfrom peripheral swirl device 70 descends in a swirling motion along rodmember 51 and through annular space 88 around central swirl device 80where it interacts with fluid emerging from central swirl device 80. Theresulting stream of fluid mixture exits the lower portion of chamber 52through a helical channel 48 machined in rod member 49. The stream offluid mixture flows downwards though helical channel 48 which furtherassists the mixing process through vortices formed along upper sharpedges of helical channel 48. Helical channel 48 also creates a quietzone which contributes to a laminar flow in the region of valve closuremember 46 for facilitating the controlling action of valve closuremember 46. Helical channel 48 in rod member 49 conveys the fluid mixturefrom the lower portion of chamber 52 to a cavity above valve seat 45.

Valve closure member 46 is preferably frusto-conically shaped andcomprises a shaped (e.g. hexagonal) recess 46 a in the lower regionthereof. The upper portion of valve closure member 46 is affixed to rodmember 49 preferably through a threaded connection. Recess 46 a in valveclosure member 46 may be utilized for screwing valve closure member 46into rod member 49. Valve closure member 46 is biased into engagementwith seat 45 by spring member 16 when no upward force is applied topiston member 23 or piston member 33. Valve closure member 46 regulatesthe flow of fluid mixture emerging from helical channel 48 to nozzle 42in accordance with the force applied to piston member 23 and pistonmember 33.

Nozzle 42 is engageable with the lower portion of lower body segment 40preferably through a threaded connection. Nozzle 42 defines a cavity 44in fluid communication with a plurality of atomizing orifices 43 whichare preferably equally spaced about the longitudinal axis of injectionvalve 1. Fluid mixture entering nozzle 42 from helical channel 48 isatomized by passing through atomizing orifices 43 and injected intoreactor 2. Atomizing orifices 43 may be inclined, for example at anangle between 5 and 30 degrees to the longitudinal axis of injectionvalve 1. The number of atomizing orifices 43 may vary, for examplebetween 4 and 12, but it will be recognized by those skilled in the artthat the number, size and orientation of atomizing orifices 43 maydepend on the characteristics (e.g. viscosity, pressure, etc.) of thefluid mixture to be atomized.

As the spray of fluid mixture from atomizing orifices 43 advances inreactor 2, hydrocarbons further disintegrate into smaller droplets thatinteract with the surrounding hot hydrogen gas. Lighter fractions startto vaporize when they reach their boiling points. In general, the rateof vaporization depends on the droplet size, boiling point of thehydrocarbon fractions and the temperature of the gas. Due to the smalldroplet size generated by injection valve 1 vaporization of lighterfractions is significantly enhanced. Hydrogen surrounding the vaporizedlight fractions readily interacts (in the presence of a suitablecatalyst) with said fractions, which improves the hydrocracking process.Furthermore, heavier fractions remaining in a liquid phase are exposedto intense heat and action by hydrogen, resulting in a more efficientcracking of long molecular chains within the heavier fractions. Thehydrocracking process in reactor 2 occurs at significantly lowerpressures and temperatures when hydrocarbons and hydrogen are introducedas described herein than in some prior art arrangements. Lower pressureand temperature lead to important savings in capital and operatingcosts.

Injection valve 1 can be operated to respond to transitory conditionsand to maintain relatively constant pressures within reactor 2.Relatively constant pressure conditions are important in obtaining alight oil product with stable hydrogen content. Pressure of the fluidmixture in reactor 2 may be regulated by providing a fluid under thesame pressure as the pressure in reactor 2 to chamber 22. This may beaccomplished, for example, by providing a portion of the fluid mixturein reactor 2 to chamber 22 of injection valve 1 through passage 60 andconduit 4 (see FIG. 2). As the pressure in reactor 2 increases, thedownward force on piston member 23 also increases. Since the diameter ofbore 21 is roughly 1.4 times the diameter of bore 25, as discussedabove, pressure changes in chamber 22 have roughly two times the effecton the force applied to piston member 23 as do pressure changes inchamber 24, or pressure changes in chamber 32. Thus, an increase inpressure in reactor 2 will increase the downward force on piston member23 and urge valve closure member 46 towards its seat 45, and a decreasein pressure in reactor 2 will decrease the downward force on pistonmember 23 and allow the upward force on piston members 23 and 33 to urgevalve closure member 46 away from its seat 45.

In some embodiments, means may be provided to maintain a relativelyconstant ratio of high-density hydrocarbon liquid to hydrogen in a fluidstream provided to the reactor in the event of a problem with thehydrogen or high-density hydrocarbon supply. For example, injectionvalve 1 may be configured to mitigate the effects of an oversupply ofoil or hydrogen to injection valve 1. In such embodiments, a passage 63in the lower portion of lower body segment 40 may be provided to removea portion of the fluid mixture in helical channel 48 when an excess ofoil and/or hydrogen is present in the fluid mixture. Passage 63 ispositioned to be in fluid communication with helical channel 48 when rodmember 49 is displaced upwards by a distance that exceeds the normalstroke of valve closure member 46. Such upward displacement may occur,for example, if the pressure of hydrogen or oil supplied to chamber 32or 24, respectively, is higher than expected, such that the upward forceon piston member 33 or 23 forces valve closure member upward past apredetermined position. When passage 63 is in fluid communication withhelical channel 48, a portion of the fluid mixture is then diverted fromhelical channel 48 to passage 63, and then through conduit 5 to agas-liquid separator 3 (see FIG. 2).

In gas-liquid separator 3 gas fractions of the fluid mixture may beseparated from liquid fractions of the fluid mixture. The separation maybe gravitational. Excessive amounts of gas cause an increase of pressurein gas-liquid separator 3 which may be detected through a pressureswitch (not shown). Gas may then be recycled by means of a valve (notshown) controlled by the pressure switch. Excessive amounts of liquidresult in a higher liquid level in gas-liquid separator 3. A levelswitch (not shown) may be utilized to detect the rise of liquid leveland open a valve (not shown) to re-circulate the liquid.

FIG. 8 shows a portion of an injection valve according to anotherembodiment of the invention. The injection valve of the FIG. 8embodiment is similar to injection valve 1 of FIG. 3, except thatperipheral swirl device 70 is positioned downstream of central swirldevice 80 in the FIG. 8 embodiment, and passage 64 a is provided inlower body segment 40 instead of passage 64. Central swirl device 80operates in the same way in the FIG. 8 embodiment as it does in the FIG.3 embodiment, except that hydrogen chambers 84 are in fluidcommunication with chamber 32 in the FIG. 8 embodiment instead ofchamber 54. The mixture of hydrocarbons and hydrogen produced by centralswirl device 80 flows outwardly through annular space 88 into chamber 54and then downwardly toward peripheral swirl device 70.

Peripheral swirl device 70 has the same construction in the FIG. 8embodiment as it does in the FIG. 3 embodiment. However, in the FIG. 8embodiment, fluids are provided to peripheral swirl device 70 in adifferent manner. The mixture of hydrocarbons and hydrogen from centralswirl device 80 in chamber 54 is provided to chambers 75 of peripheralswirl device 70 through bores 71 and 72 in screws 73. The mixture isthen expelled from nozzles 76 into aperture 79.

As best seen in FIG. 9, annular groove 62 a is not machined around theentire inner surface of bore 82 in order to form two shoulders 40 a and40 b. Shoulders 40 a and 40 b abut two different plates 74, and arepreferably disposed symmetrically with respect to the longitudinal axisof the injection valve such that annular groove 62 a is divided into twoequal portions. Hydrocarbons are provided to some of spaces 78 throughpassage 62 and one portion of annular groove 62 a. Hydrogen is providedto the remaining spaces 78 through passage 64 a and the other portion ofannular groove 62 a. The hydrocarbons and hydrogen in spaces 78 areexpelled through nozzles 77 into aperture 79, where they are mixed withthe mixture being expelled from nozzles 76. The resulting mixture thendescends towards helical channel 48 as described above.

While a number of exemplary aspects and embodiments have been discussedabove, those of skill in the art will recognize certain modifications,permutations, additions and sub-combinations thereof. For example, aswirl device having a different construction than the specific examplesdescribed above may be provided which introduces a swirling motion tomix fluids. It is therefore intended that the following appended claimsand claims hereafter introduced are interpreted to include all suchmodifications, permutations, additions and sub-combinations as arewithin their true spirit and scope.

1. A method for introducing a high-density hydrocarbon liquid into ahydrocracking reactor, the method comprising: atomizing the high-densityhydrocarbon liquid; and, injecting the atomized liquid into thehydrocracking reactor.
 2. A method according to claim 1 furthercomprising: mixing hydrogen with the high-density hydrocarbon liquidprior to atomizing the high-density hydrocarbon liquid.
 3. A methodaccording to claim 2 wherein mixing hydrogen with the high-densityhydrocarbon liquid comprises providing a swirl device and providing thehydrogen and high-density hydrocarbon into the swirl device causing eachof the hydrogen and high-density hydrocarbon to undergo a swirlingmotion prior to mixing the hydrogen and high-density hydrocarbon.
 4. Amethod according to claim 2 further comprising: regulating a pressure inthe hydrocracking reactor by controlling a rate at which thehigh-density hydrocarbon liquid is injected into the hydrocrackingreactor.
 5. A method according to claim 4 wherein regulating thepressure in the hydrocracking reactor comprises: providing a pistoncoupled to a valve configured to control the rate at which thehigh-density hydrocarbon liquid is injected into the hydrocrackingreactor; and, delivering a portion of a fluid mixture in thehydrocracking reactor to a chamber adjacent to the piston such that anincrease in the pressure of the fluid mixture produces a force on thepiston which causes the valve to reduce the rate at which thehigh-density hydrocarbon liquid is introduced into the hydrocrackingreactor.
 6. A method according to claim 2 further comprising a step formaintaining a relatively constant ratio of high-density hydrocarbonliquid to hydrogen in a fluid stream provided to the reactor in theevent of a problem with a supply of high-density hydrocarbon liquid orhydrogen.